Our workflow requires users that create New Tasks to enter a certain set of data (product size, product title, brand name, formula number, etc.). Add customizable fields like this to Task Creation and include a "lock" that will not allow tasks to be created without this data set, i.e., as with any web form that has "required fields".

When I am invoicing it would be so nice to be able to select/check multiple time entries and have the total appear for the checked items. Then when I'm invoicing I could easily add up the time for a specific task or tasks instead of exporting the time entries as a .csv and using excel to do the math or adding the time/totals myself.

Add a per-project kanban board with the classical icebox, to-do, work in progress, done columns, and a cross-project one which gathers all task for a team in all the projects and allows one-point-managing of the whole thing

Tasks can have a priority (which is fairly limited) but projects cannot. It would be great if projects could be assigned a priority and even better if the priorities were customizable.

I would need tasks assigned to tasks, if you had this I would buy.

the ability for project owner to reset password or to send email to contact to retrieve password.

Often you have a multitude of subtasks that you don't want to see on your Calendar. Sometimes you might want to see all subtasks.

Why not have a filter for both of these views on Calendar?

In a calendar view see who are connected to a task or an event

Further customization beyond the two choices for page theme and 7 choices for color theme. If your brand does not match those colors that you will not be able to "seamlessly" integrate the system with your site. The is really a key feature in my opinion. Perhaps it would be simple enough to put a color picker in there for each of those two elements if you are not up for a full blown brand integration feature.

It should be possible to make changes to a conversation. Eg: I’ve just made a conversation and saved it, but now I see a typo…This means I have to delete the conversation and start over.

Syncing tasks with mail would be a huge benefit. Being able check off completed tasks in mail would be great.

Because adding estimated time to individual tasks is fabulous, but if they are nested under a parent task, it is a pain to manually calculate the estimated time for each task and add it to the parent task. Also, the amount of time required for each parent task is needed to help plan how long each task should take.

Evernote is a very popular tool for taking notes, etc. Recently, the API was made available, making it possible to integrate (see eg. pelotronics). For companies already using evernote, or for companies that have requirements for offline notes (evernote has client apps for mac, windows, iphone, android, etc.) such integration might be very valuable.

Tasks should sync with task list in Outlook.